In the case of networks which are particularly relevant to safety, such as in automation plants or latterly also applications in the automotive sector by way of example, data which is particularly relevant to safety must continue to be transmitted even in the event of potential faults in hardware components or transmission paths.
Synchronized communications systems by way of example are used in real-time systems and these employ for example AFDX (Avionics Full Duplex Switched Ethernet), TTEthernet in the case of aircraft applications or for example Profinet IRT (Isochronous Real Time) in automation networks. High priority data is exchanged between the network nodes in a specified time slot. Highly accurate synchronization of the network users among themselves is necessary. High priority messages are not dealt with either in the event of faulty synchronization and this can lead to failure of the communications system. Redundant communications systems having different synchronization mechanisms are often used to prevent corresponding synchronization errors and provide a secure network. This leads to usually increased cabling and hardware expenditure.
In this respect it is desirable to provide, in particular for network applications relevant to safety, network operation and network systems which reliably perform their task even in the event of synchronization difficulties.